Treatment of textile materials



Dec. 6 1938. D. FINLAYSON ET AL TREATMENT OF TEXTILE MATERIALS Filed June 4, 1937 Patented Dec. 6, 1938 UNITED STATES,

TREATMENT OF TEXTILE MATERIALS Donald Finlayson and Richard Gilbert Perry, Spondon, near Derby, England, assignors to Celanese Corporation of America, a, corporation of Delaware Application June 4, 1937, Serial No. 146,378 In Great Britain July 30, 1936 6 Claims.

The present invention relates to an improved process for the treatment of textile materials and is concerned more particularly with the treatment of artificial filaments, fibres and the like (hereinafter referred to for brevity as filaments).

Continuous artificial filaments differ from niaterials such as cotton and wool in that the artificial filaments are relatively smooth and do not contain the minute crinkles or crimps which occur naturally in cotton and wool fibres and which are largely responsible for the characteristic handle, fullness and elasticity of such materials. Moreover, the naturally-occurring crinkles or crimps in cotton and wool fibres assist in the interlocking of the fibres in spinning operations and thus promote the coherence which results in the good spinning properties of the fibres. Thus. when spinning staple fibre produced from artificial filaments in machinery of the type used in the production of cotton or wool yarns, the smoothness of theartificial material allows of excessive slip between the fibres, with the result that a sufiicient degree of coherence is diificult to obtain and the spinning process is rendered generally more difficult.

It is an object of the invention to improve the handle or feel and spinning properties of artificial filaments and generally to impart to such filaments a crimped structure akin to that of cotton or wool fibres.

According to the invention artificial filaments are laid across each other in a cries-cross manner and while so disposed are softened, subjected to mechanical pressure and dried and set. Thepressure forces the softened filaments into intimate contact with each other and induces in the filaments minute waves or crimps at the point at which the filaments cross each other with the 40 result that the filaments assume a generally crimped structure. The treated filaments are allowed to set and dry in the compressed state, and on completion of the process are found to have a full, springy handle or feel and an enhanced covering power.

The filaments may be softened by applying thereto any suitable substance having asolvent or partial solvent or softening action on the ma terial of the filaments, or, if desired, a'hotaqueous medium such as steam or hot water may be applied to the filaments to soften them.

Continuous or long lengths of filaments treated according to the invention may be parallelized and converted into relatively short staple lengths, (e. g. by cutting) for spinning on cotton-or wool machinery in the manner of cotton or wool fibres, or, if desired, untreated continuous or long lengths of filaments may first be converted into relatively short staple lengths and the staple lengths may then be treated in the manner described above,

i. e. by softening and pressing a criss-cross mass of the staple lengths.

Yarns and fabrics containing the filaments treated according to the invention assume characteristics of the component filaments in that they have a full springy handle or feel and have enhanced covering power.

While the invention is applicable to the treatment of artificial filaments in general, it is of especial value in connection with the treatment of filaments of organic derivatives of cellulose, e. g. cellulose esters such as cellulose acetate,

cellulose formate, cellulose propionate and celluose butyrate, and celulose ethers such as methyl,

(e. g. one to two or more inches if fibres resembling cotton are to be produced, and three to seven or more inches if fibres resembling wool are to be produced) and the short lengths are opened and loosened by scutching. I l

The loose fibres are then arranged in criss-cross layers or groups in a circular chamber i having a perforated false bottom 2, the layers being built up until the chamber is substantially filled. A loose perforated plate 3 shaped so as to fit closely to the sides of the chamber I while being freely movable vertically within the chamber is then placed on the top of the fibres and forced downwardly by a hand-wheel and screw device 6, the screw of which passes through a fixed threaded block 5 and bears against a raised portion 6 of the plate 3. The raised portion 6 is formed with a suitable dimple for the reception of the rounded end of the screw.

The plate 3 is pressed downwardly by thescrew l until the fibres are forced into intimate contact with each other, a pressure of about lb. per square inch being sufiicient to induce .minute waves or crimps in the filaments at the points at which they cross each other. When such pressure is reached, the rotation of the screw is' stopped and a circular lid 1 formed at its centre with a threaded boss 8 and engaged and carried by the screw is rotated about thescrew until the edge of the lid comes tightly into contact with a packing ring 9 disposed around the top of the chamber i.

On the chamber i being thus charged with compressed crimped fibres and closed by the lid 1, steam or hot water is admitted to the top of the chamber through a pipe Ill controlled by a valve II. The hot aqueous medium is forced through the compressed fibrous mass and passes through the perforated bottom 2 of the chamber, the medium exhausting from the chamber through a drain 12 which is controlled by a valve l3. In this manner the compressed fibres are softened while in the crimped condition with the result that the structure of the fibres is modified and conformed to the crimped condition.

Where steam is employed as the softening medium the temperature is preferably at about 135 C., and the pressure in the chamber is maintained at about 25 lbs. per square inch.

When the compressed fibres have been subjected to the action of the hot aqueous medium for about one hour the valve II is closed to cut oil the supply of the medium, and a drying current of hot air ispassed into the chamber from a pipe l4 controlled by a valve I5. The hot air is forced through the softened fibres and escapes from the chamber through the drain I 2, the fiow of air being maintained until the fibres are dried and set in their crimped condition,

After drying and setting the lid 1 is unscrewed and the mechanical pressure on the fibres is released, the now crimped and set fibres being removed from the chamber in readiness for spinning. The chamber may then be used for crimping a further supply of material. It is found, when steam is used as the softening medium, and especially when at elevated temperature and pressure, that the drier the steam the softer is the handle or feel of the treated fibres.

In accordance with another method of crimping according to the invention cellulose acetate or other organic derivative of cellulose fibres of say 2 inches in length are softened by being soaked for ten minutes in a 30% by volume solution of acetone and water, the softened fibres then being placed in the chamber 2 and subjected to pressure and dried and set in the manner described above, no hot aqueous medium, of

course, being passed through the material during the process. If desired the fibres may be soaked while in the chamber, it merely being necessary to connect the pipes I 0 and I2 with a suitable supply of acetone and water which may pumped or otherwise circulated through the chamber for the requisite period prior to drying. Cellulose acetate fibres crimped after softening with acetone and water are found to have a characteristic curl or wave.

Artificial fibres crimped according to the invention may be spun into yarn and woven into fabric either alone or mixed with wool and/or cotton or other textile fibres. When mixed with other fibres pleasing cross-dyed effects may be obtained by subjecting the yarn or fabric to the action of a dyestufi having afiinity for one class of fibre only. The remaining fibres may be left undyed or may be dyed different colours.

Having described our invention, what we desire to secure by LettersPatent is:-

1. Process for the production of crimped artificial filaments, which comprises laying filaments -of a thermoplastic material across each other in a criss-cross manner, and while they are so disposed subjecting the filaments to mechanical pressure, applying a hot aqueous medium to soften the filaments while the mechanical pressure is maintained on the filaments, and then drying and setting the filaments by passing a drying medium therethrough while the mechanical pressure is maintained,

2. Process for the production of crimped artificial filaments, which comprises laying filaments of cellulose acetate or other thermoplastic derivative of cellulose across each other in a criss-cross manner, and while they are so disposed subjecting the filaments to mechanical pressure, applying a hot aqueous medium to soften the filaments while the mechanical pressure is maintained on the filaments, and then drying and-setting the filaments by passing a drying medium therethrough while the mechanical pressure is maintained.

3. Process for the production of crimped artificial filaments, which comprises laying filaments of a thermoplastic material across each other in a criss-cross manner, and while they are so disposed subjecting the filaments to mechanical pressure, passing steam through the compressed filaments to soften them while the mechanical pressure is maintained on the filaments and then drying and setting the filaments by passing a drying medium therethrough while the mechanical pressure is maintained.

4. Process for the production of crimped arti-- ting the filaments by passing a drying medium therethrough while the mechanical pressure is maintained.

5. Process for the production of crimped artificial filaments, which comprises laying filaments of cellulose acetate or other thermoplastic derivative of cellulose across each other in a criss-cross manner, and while they are so disposed subjecting the filaments to a mechanical pressure of about pound per square inch, passing steam through the compressed filaments to soften them while the mechanical pressure is maintained on the filaments, and then drying and setting the filaments by passing a drying medium therethrough while the mechanical pressure is maintained.

6. Process for the production of crimped artificial filaments, which comprises laying filaments of cellulose acetate or, other thermoplastic derivative of cellulose across each other in a criss-cross manner, and while they are so disposed subjecting the filaments to a mechanical pressure of about Apound per square inch, passing steam through the compressed filaments at a temperature of about C. and at a pressure of about 25 pounds per square inch to soften the filaments while the mechanical pressure is maintained on the filaments, and then drying and setting the filaments by passing a drying medium therethrough while the mechanical pressure is maintained.

DONALD FINLAYSON.

RICHARD GILBERT PERRY. 

